B1000 on Chevrolet: How to Diagnose & Fix
ECU/Control Module Internal Malfunction (manufacturer-specific)
1 Chevrolet model · 1 documented issue · 1 critical
B1000 on Chevrolet by model: symptoms, diagnosis and fix
The 2003-2006 Impala was included in the massive GM ignition switch recall affecting millions of vehicles. The ignition switch has a weak detent spring that allows the key to slip from the "Run" position to the "Accessory" or "Off" position while driving. When this happens, the engine shuts off, the power steering and brake boost are lost, and the airbags are disabled — all without warning. The issue is exacerbated by heavy key chains that add weight and leverage on the ignition cylinder. This defect was linked to numerous fatalities.
Common Symptoms
- Engine shuts off unexpectedly while driving
- Key turns to accessory position on its own
- Airbag warning light illuminated
- Power steering lost suddenly
- Dashboard goes dark momentarily while driving
- Stalling when hitting bumps or turning
How to Fix
Check the NHTSA recall database (NHTSA.gov) with your VIN — this is recall 14V-394 and the repair is FREE at any GM dealer regardless of mileage or ownership history. The dealer replaces the ignition switch assembly with an updated design that has a stronger detent spring. Until the recall is completed, remove all extra keys and accessories from your key chain — use only the vehicle key with nothing else attached. NEVER ignore this recall; it is a critical safety issue.
Sources for this issue (1)
B1000 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does B1000 mean on a Chevrolet?
B1000 stands for "ECU/Control Module Internal Malfunction (manufacturer-specific)." B1000 is a manufacturer-specific body (B) code that generally indicates a control module has detected an internal failure during a self-test. The exact module varies by maker: on Toyota/Lexus it typically points to a fault in the airbag (SRS) control computer, while on GM and some others it is a more general ECU malfunction flag set by the body control or airbag module. When tied to the airbag system it is safety-critical because it can disable airbag deployment. The specific module and meaning should be confirmed with the vehicle's service data. On Chevrolet it is documented across 1 model: Impala.
What are the most common causes of B1000?
The most common causes of B1000 are: Internal fault in the airbag (SRS) control module, Faulty body control module (BCM) or other networked module, Internal memory/processor self-test failure, Power supply or ground problem to the module, Water intrusion or corrosion damage to the module, Module software corruption, Previously deployed or damaged airbag system component. The specific cause varies by vehicle.
How much does it cost to fix B1000 on a Chevrolet?
Repair costs vary widely with the root cause and Chevrolet model; each issue on this page carries its own estimate where one is published.
Looking for B1000 on a different make?
View B1000 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.